Microsoft/TypeScript
在 GitHub 查看Inferred type is not the same as what's passed in original generic type.
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#42,516 创建于 2021年1月27日
BugDomain: check: Type InferenceEffort: DifficultHelp Wanted
描述
Bug Report
🔎 Search Terms
infer, generic
🕗 Version & Regression Information
- This is a crash
- This changed between versions _________ and _________
- This is the behavior in every version I tried, and I reviewed the FAQ for entries about infer.
- I was unable to test this on prior versions because _______
⏯ Playground Link
Playground link with relevant code
💻 Code
// The variable names are meaningless, they are simplified from vue project.
type PropConstructor<T = any> =
| { new (...args: any[]): T & object }
| { (): T }
type MyInfer<T> = T extends PropConstructor<infer V> ? V : 'xxx'
type VVV = (() => string) | (() => number)
type X = MyInfer<PropConstructor<VVV>>
🙁 Actual behavior
type X = (() => string) | (() => number) | ((() => string) & object) | ((() => number) & object)
🙂 Expected behavior
type X = (() => string) | (() => number))